The present invention relates to a vacuum cleaner and to a suction nozzle body thereof; and, more particularly, the invention relates to a vacuum cleaner comprising a suction nozzle having a rotary brush (in particular a rod shaped member constituted by a rotary impeller member having a brush member wound thereon in a spiral shape) and in which a suction force can serve as a driving power source to rotate the brush member, and to a suction nozzle body thereof.
In conventional vacuum cleaners, in particular those with a suction nozzle having a rotary brush in which the suction force serves as a driving power source to drive the rotary brush, the rotation of an impeller is transmitted to the rotary brush through a pulley member or a belt member. With such a structure, since the impeller and the rotary brush are mounted as separate elements, the whole suction nozzle body becomes large and is heavy.
Thus, as described in Japanese patent laid-open publication No. Sho 63-214,217 and Japanese patent laid-open publication No. Sho 64-58223, it has been proposed to provide a suction nozzle having a rotary brush which is rotated integrally with an impeller and is mounted on the same shaft therewith, and a suction nozzle body forming a turbine chamber which encloses the impeller using a partition wall. Further disclosures of the above stated kind of apparatus are provided in Japanese utility model laid-open publication No. Sho 54-177,170 and Japanese utility model laid-open publication No. Sho 57-69,665.
Among the above-stated conventional techniques, in an apparatus wherein the rotary brush of the suction nozzle body is driven by an impeller mounted on another shaft, the volume of the impeller is large, and, as a result, there is a problem in that the size of the suction nozzle body becomes large. Further, since the impeller rotates with a rotation speed about from three times to four times that of the rotary brush, there is a problem in that substantial noise is generated.
Further, in an apparatus wherein the impeller and the rotary brush are mounted on the same shaft, the air sucked from outside of the suction nozzle body passes through a surface to be subjected to cleaning. The air transports dust swept up using the brush member or the blade member of the rotary brush, after which the air passes through the suction nozzle body. The air enters into the turbine chamber which is enclosed using a partition wall and collides with the impeller and generates a torque.
When the suction nozzle body is lifted up, since the resistance against rotation of the rotary brush becomes small, the rotary brush rotates with an abnormally high speed of rotation, and so increased noise is generated. Further, since the suction inlet is exposed, if an operator accidentally inserts his or her fingers into the suction nozzle body, there is a problem that they may be injured.
Further, since the dust on the floor passes through the nozzle, it is impossible to make the cross-sectional area at the nozzle outlet small, thereby it is impossible to increase the velocity of the air flow which impacts and drives the impeller. As a result, there is a problem in that it is difficult to generate a sufficient torque for rotation of the rotary brush.